Wow, all this talk about worn cams and wobbly distributors does not make sense to me. Nor does the points closing up, since he re-tuned it after the problem showed up.

As I read it, the car was running fine until he filled up, so it sounds like bad gas...perhaps a load of water got in there and filled the back float chamber, but somehow managed to bypass the front one? Or perhaps the gas he got had a fairly high ethanol content and disloged a chunk of trash and clogged up that carb.

Either way, it sounds like a simple clean-up of the carbs is in order along with a new fuel filter, and perhaps a draining of the fuel tank if it turns out there is water in the carbs.